BTW I did purchase the OS maps with the 650T but they came on an SD card

Well then I'm still confused. ;) What does the "T" mean on the 650T? On the US models, "T" means "Topo" and it is pre-loaded on the GPS in the gmapprom.img file. So why did you have to purchase the map separately?

GMAPPROM Topo was on the 650T, the Ordnance Survey maps are totally independent being the government national mapping setup. These were sold as a part of the bundle on an SD card as they had routing. They were not layered, effectively just a scan so they were unreadable in close-up and upside down when going North to South! Other problem was it meant you had to use that SD card so severely limited storage on the device.

OK, now I understand. :) But to make sure the horse has been fully beaten to death, if you get a Montana, why would you choose the 680T instead of the 610? Because you like whatever topo is bundled with the 680T?

The OS maps as supplied to me were routable and had post code search etc. If another map was hidden within it I was not aware. I contacted garmin to ask if I could load the OS maps onto internal memory and was told I COULD NOT.

Re 680 and 680T you are correct apart from the 680T having slightly more memory. As I do not use the Topo map and deleted it from my 650T the extra money is not worth it for 0.2 gig more of memory.

No, it's a common misconception, the OS map itself isn't routeable (try routing down the footpaths). It will only route along the road network because it also contains Garmins CN map that covers the UK, which also gives you the postcodes. Garmin are correct that if the maps came on a card they cannot be transferred to the internal memory, as they are locked to the card.

That explains how the OS maps routing still worked when zoomed in to a level where they were unreadable. I don't know if the newer ones are any better with multi levels from the different scale OS maps available but would suspect not.

We've gone a bit off-topic for the 276Cx!! which incidentally I don't think I can justify twice the price of a 680 on

No, they're not any better because they are simply copies of paper maps, in a raster format, which is why they blur as you zoom in. OSM mapping, like talkytoasters and others, is vector mapping so remains sharp as you zoom in and is generally routeable.

We've gone a bit off-topic for the 276Cx!! which incidentally I don't think I can justify twice the price of a 680 on

This really brings us back on point. The market for this kind of device is really going to be limited to people with disposable income and expensive hobbies. The $800 price tag is going to be a problem for the rest of us.

It's big!Doesn't quite have the solid chunky feel that the 650T had.Screen is less recessed than the 650T wasn't going to use a protector but think I will.D ring is fiddly and cover sticky to get off compared with 650T but may be closer fitting which would be better..Absolutely amazed it has an out of date mini USB socket and not micro USBScreen seem very bright compared with 650t

Hopefully will get to try the beast today. Last night's charge was just over an hour for each 10%, very long time,Quick plays showed two things I don't like;1) The power button is not protected and will all too easily be turned on in the pocket.2) I have reset to defaults twice so far (grrrrrrr!) whilst trying to set it up to my liking. The restore option appears to come up as top highlighted option when exiting some of the menus.

TalkyToaster maps work on it and do look good, interesting screen display option of overlay whereby the data fields have transparent backgrounds, good for exploring the maps but may not be clear enough in sunlight on the bike.

Pottered around the block and tried a couple of very short routes and briefly it does everything the Montana did and more. My redundant Montana mounts all fit it.

Screen is definitely better than the Montana, bigger and brighter and just looks nicer.Additional nice feature of battery life predictor alongside the brightness slider, 70% brightness is quite bright and suggests 19 hours! full brightness suggests 9 hours, very good!

Have set it up exactly as my Montana was, takes a bit of intuition as the manwell is cr@p, not a single screen prompt display in it. EG main menu tabs disappear off the RH side of the screen with no indication more options are there and the display/volume/battery life popup or its functionailty is not mentioned at all.

All the profiles in the Montana are there plus more features. I like the popup warnings of approaching turns and it's definitely easier to anticipate turns. Remember my target vehicle is Motorcycle/electric pushbike.

Got used to the buttons quite quickly, though have yet to stop prodding the screen on occasion!

Software seems a little jagged at the edges in places, but it is a brand new machine and that can be rectified. For example calibrating the altimeter to a known height - there is no backspace key on the displayed keypad, so make a mistake and you have to overwrite the first numbers with leading zeroes to get it right or be at the top of Everest!

Lots of functions I will never use such as marine mode / weather wifi etc (nor the marine mount with its bare wires), but I think that the 276Cx and I are going to be friends when we get to know each other better.

Nearly thrown the 276CX out of the window a few times trying to find stuff that the manual gives you no help on, but slowly getting used to the idea that keys are multi-function and if you keep pressing them different things happen. These menus do give access to an awful lot of functionality and customisation.

Noticed there is no security lanyard tag on the 276CX, a cheap and nasty omission, given the value of the thing and my previous experience! It's really designed for mounting and, with its non recessed power button, not designed for putting in the pocket. Even so I always used to loop the Montana lanyard over the handlebar mount in case it popped out.

Will be doing an all day job on Wednesday and should have a better idea of performance and battery life.

Had another look at that ADVrider thread that was linked to earlier (26 pages long now). Wonder if the honeymoon is over? Several people are saying screen refresh is slower than the Montana and Monterra (the 276cx has about 3x as many pixels to update). A couple people say they're returning theirs...

The Good: Battery life is superb, used it nearly all day yesterday and had loads of battery remainingThe Bad: The screen refresh rate is absolutely awful under full screen and travelling. It is virtually unusable.The Ugly: Lack of portrait mode makes it quite difficult to hold as a handheld.

So many good features but am seriously considering returning it before the 14 days UK cooling off period are up.

Video of 276CX refresh with three maps working (preloaded recreational, Talktoaster TT and Cache)The preloaded map is the worst.

Emailed Garmin and was told they would refund even though it had been opened, no argument whatsoever. I guess they know of the problem.

Sadly it's on its way back to Garmin, very disappointed as it looked so good. No way I can see them fixing that bad a display problem by software alone, requires more clout. Rest of the problems were easily fixed software shortcomings.

As soon as I tried it with just the TalkyToaster map loaded and cycling around the block I realised that the GPS was always showing slightly behind my actual position, but thought little of it until I saw the stress it was under the first time it moved at 50mph.

Back to researching the 680 I guess, unless rumours of an uprated 276CX surface

I've long wondered how many seconds or fractions of a second is the position shown on the map is from what the actual position when moving. And if you are using a remote device such as a computer to view the data, then the lag between shown and actual is even more.

I once ran a sailboat aground just after midnight while navigating a tricky entrance to a bay I'd never visited before. I was at the helm and the captain was using a remote display on a computer. Even though my eyes told me better, I had to follow the Captains course directions. That's when I (and the Captain) first became acutely aware of the issue of lag between actual and shown position. We later learned that the position shown on the computer could be as much as five seconds behind, which meant as much as 50 ft error when going 6 knots which then has to be added the possible 30 ft uncertainty of the gps position.

GPS manufactures don't give us this piece of information. Of if they do I'm oblivious to the term they describe it by.

As for the grounding. Luckily the tide was just about to be at it's lowest, so all we had to do was sit tight and BS a few hours for the tide to rise and lift us up.

AFAK, all of Garmin's handheld and automotive devices update your position once per second - notice that one track point per second is the most you can record in a log for example. So your position could be more than 80 feet off if you are travelling 60 MPH. Now from what I've observed on the Nuvi, the screen refresh is faster than 1 frame per second, however I believe your position is interpolated with the assumption that your velocity and heading have not changed since the last actual position update.

Now the Garmin GLO bluetooth receiver provides 10 fixes per second. They have positioned this device for private aviation use, and you can cover a lot more distance in one second in an airplane. That is how fast the GLO supplies the data. It is up to the device it is paired with to read the data and display your position on the screen, so there is bound to be some variation.

I saw a fair amount of variation in my GLO tests with Android, iOS and Windows 7 using different apps. None of them were able to record a full 10 track points per second. IIRC, I was getting around 7 using Galileo on iOS. But motion appeared much more fluid using the GLO vs the phone or tablet's built-in receiver. And it was more responsive to small movements. For example, the map would rotate to show rapid "zig zags" while driving.

I can get a pretty good sense of what this means by using maps I've made from USGS High Resolution Orthophotgraphy (HRO) at one foot per pixel. Zoom way in and you can see exactly where the GPS thinks you are.

A 5 second delay is pretty unreasonable. I don't think you will see that on any current device.

I don't think that you can assume that the frequency of the log updates has anything to do with the frequency of the screen updates. On many of Garmin's devices the frequency of log updates is a setting that can be controlled by the user. I've felt this is just to allow users to control how fast the log file increases in size.

I'd think as far as updating their own display most devices are doing at least the 10/second that the GLO reports if not more. But that is one of the components of the issue that you don't typically find data published:

How often is a position updated sent to other devices attached device?

And the other and bigger part of the issue for me is:

how old is that position data

It might be that this information is in the data packet transmitted, but I never have looked into it that closely. It was 10 years ago when I toyed with the idea of writing my own program to use the nema and seatalk info from my marine gps to display data on my tablet, but I never got past a casual look into the communication formats of nema, which showed it to be fairly straightforward, but more work than I wanted to do at the time.

Well, believe whatever you like. ;) It has been widely accepted that Garmin's handheld and automotive devices provide one gps fix per second and I have never seen anyone claim otherwise. The nuvi has an advanced track recording mode in a hidden engineering menu that provides the raw data in fact.

Garmin makes a point about the GLO having such a high update rate. There are a few bluetooth devices from other companies that have high update rates, but 1 fix per second has been the norm in the past.

As far as how many frames per second the GPS screen displays, I don't know, clearly it is more than one per second on any modern device. But that is just a function of the display software.

Emailed Garmin and was told they would refund even though it had been opened, no argument whatsoever. I guess they know of the problem.

Sadly it's on its way back to Garmin, very disappointed as it looked so good. No way I can see them fixing that bad a display problem by software alone, requires more clout. Rest of the problems were easily fixed software shortcomings.

As soon as I tried it with just the TalkyToaster map loaded and cycling around the block I realised that the GPS was always showing slightly behind my actual position, but thought little of it until I saw the stress it was under the first time it moved at 50mph.

Back to researching the 680 I guess, unless rumours of an uprated 276CX surface

I got that same impression looking over the advrider thread and all its links. Lots and lots of stuff there. I don't think they gave it a good enough engine and as usual with Garmin's new devices the software is buggy, so I'll stick with the old original 276C as long as I can keep it running.

This is an important feature to me, the ability to zoom out and get an overview of the smaller roads...and a feature that old fashioned paper maps have GPS beat by far...

"One capability that has been absent from Garmin devices since the discontinuance of the x76 Series Chartplotter's was the ability to see more (minor) road data on the Map page at higher map-scales. Most of Garmin's current devices with 5" displays have a resolution of 800x480 pixels and it was thought by many that they just didn't have the pixel density to show more data at zoom levels above 0.8mi(1.2km). Well, guess what?!

Garmin has pushed the zoom detail about as far as they can on this new 276Cx as long as you're using third-party maps like those from OpenStreetMap (OSM) or Garmin Topo Maps. If you are, you will see minor roads out to a scale of 2mi (3.2km)! If you want to use Garmin's City Navigator maps, minor roads will still disappear after the .8mi(1.2km) scale as they do on all current Garmin devices...

This is an important feature to me, the ability to zoom out and get an overview of the smaller roads...and a feature that old fashioned paper maps have GPS beat by far...

Fact is, this is an issue with the map and not the GPS hardware. I make my own maps that show little dirt roads as far out as you like. This works on any Garmin device. The hardware issue is that the more roads you show, the longer it takes the device to update the screen, possibly even crashing it.

I have addressed that problem in my own maps by assigning a custom zoom level for every road. a feature that is available in Garmin's map format but AFAIK, nobody else has taken advantage of it.

Other maps assign zoom level by road class - for example, all minor roads will disappear at .8 miles. On my map, I use logic to determine whether each segment of each road should be shown. So, for example, roads in densely populated areas disappear sooner than roads that run through the middle of nowhere. This adds a fair degree of complexity to the map creating process, but I've gotten good results.

Unfortunately, I just don't have time to spend making maps at the moment so I haven't publicly released any maps made with this technique.

"Since I am not currently in a position to do further testing on the GPSMAP 276Cx, based upon my last set of tests (pre-v3.00) and Greg's further updates, I have removed the GPSMAP 276Cx from my Recommend List and updated my review article accordingly. "

This is crazy, a 276cx owner in the EU (Spain I think) was told by Garmin support that the use of non-Garmin maps was not only un-supported but it would actually void the warranty. He posted the info from Garmin in Spanish and someone else posted a translation:_________________________

"Installed Cartography: Please note that the use of non-Garmin mappings may lead to malfunction of the unit, in case of receiving the equipment and a malfunction due to it, a charge of 1 hour of labor will be charged (€ 55 + VAT) for equipment inspection expenses for an item outside Garmin, since this failure is not due to a defect of origin or of the product itself."

"...be aware that inserting maps other than Garmin will lead to the loss of the warranty."_________________________

There is no indication that Garmin USA is adopting such a policy. If they did, I think it would be suicidal. Geez...

But the map restriction seems like part of a pattern that is emerging. From what I've read, newer Garmin marine gps units will not display a map unless a Garmin copyright is embedded in the data. And there are evidently some new EU automotive (Drive/Nuvi) models that won't display third party maps either.

I think Garmin owes a lot of their success to the availability free maps. I guess they are getting good enough to worry them. Not a very smart policy IMO, their piece of the pie is already shrinking and this is like a slap in the face of people who pay a lot of money for their hardware.

Looking at Garmins warranty I can see nothing about 3rd party maps but there is this clause

(v) damage to a product that has been modified or altered without the written permission of Garmin

which I suppose could be used to void the warranty should installation of a 3rd party map brick a device, in my view I feel Garmin would be within their rights to do so. It's why I always place 3rd party maps on a SD card just in case they cause an issue, got caught that way a few years ago now and needed GarminCure to unbrick my nuvi!

Just noticed, GPSCity is now selling the GPSMap 276cx for $480 (new) or $440 (refurb). That is quite a price drop from the original $800. If it had originally been priced at this level, I might have bought one. Today.... not so interested.

It's curious that they still sell the automotive bundle (that includes lifetime City Navigator and a mount) for $700 and the motorcycle bundle for $800. Phew, that's a heavy premium for a map and mount. ;)

But - curiously - the prices of their automotive devices have fallen much more in line. For example, at that same site, you can get a refurbished Drive 60LM for $50. That may be some kind of "cyber week" special, but not bad for a device with a 6" screen and lifetime maps.

And the top of the line DriveSmart 61LMT is $180, not unreasonable for a beautiful 7" screen with almost no bezels. I got mine about a year ago and think it was around $250.

I'd say Garmin is just charging what the market will bear. Like many members of this site, some people don't think it's a GPS unless it has a Garmin logo. Such a captive audience will just have to pay the "Garmin Tax" if they want a new device. :D